At an event at Union Station today where Vice President Joe Biden was heralding the $1.3 billion in investments in rebuilding train stations and passenger rails, a microphone picked up one of the former senator's myriad Senate colleagues addressing him, formally, as "Mr. Vice President."

That met with Vice President Biden's standard reply.

"Gimme a f*&$#ing break," he said, apparently unaware that the microphone was on.